Hiya! I'm so sorry it has taken so long for you to get a reply- sometimes people dont have any helpful advice, so they dont post.
Well i guess i can understand your fears about having a medical record say "mental illness". This can be a valid concern for people who want to work in special professions where medical checks are necessary. For other people it is a matter of pride- they just don't want others (even medical professionals) to know.
For what its worth, your doctor cant actually share your info with anyone else- even other medical professionals, unless you say so. its called doctor-patient confidentiality. It might only come up if you were referred to a specialist or hospital, and that info was relevant.
However, you dont want to to go the doctor. Thats fine. Have you looked into private Health Insurance? Hospital can be expensive, but you can get Extras cover on its own. I suggest this as Extras cover for myself only costs $10 a week but i get to claim $550 of psychology, as well as physio, optical, dental... So you can go to a psychologist or counseller without a doctors referral, and simply pay for it yourself without involving medicare- or you can claim it through Extras insurance.
I know there is a free 10 week Cognitive Behavioural Therapy course you can do through MindSpot Clinic (google MindSpot Clinic and go to their webpage). While it is free, you do need to tell them your medicare card number- i'm not sure if you're willing to do that?
There are other CBT courses- simply google them. Some you pay for yourself, some are medicare-funded. You could try reading therapy books perhaps- maybe look on Amazon or your local bookstore and see if you can find some books on anger management?
Also try googling "anger management support group", or simply "support groups". I'm sorry i cant help further, i'm in Melbourne, and the only support groups ive been to are anxiety and depression ones.
Please keep us updated with how you go finding a course or therapy or book! I'm sure there are others who would appreciate this information.
For now- every time you want to lash out verbally or physically at your partner, put every amount of energy you have into walking away. Go and scream at a wall, bash up your pillow. You'll learn MUCH better techniques through a therapy or a good book, but thats all i can suggest just to get you through until you find something :)